Ozonating apparatus for drinking water

ABSTRACT

With this apparatus ozone gas is automatically applied to contaminated water in a contact tank, and is then transferred to a discharge tank in such manner that contaminated water cannot accidentally pass from one to the other tank, when the system is on automatic operation. Electrical controls responsive to sensing means disposed exteriorly of the contact tank, and responsive to predetermined changes in the weight or level of the water in the contact tank, automatically replenish the supply of ozonated water in the discharge tank, when necessary. A system is also disclosed for supplying ozone gas to a system selectively, and one at a time, from one of a plurality of ozone generators to prevent undue overloading of the generators, but the circuit to pump motor 46&#39;&#39; may be temporarily interrupted as noted hereinafter.

United States Patent 91 Troglione Jan.8,1974

[ OZONATING APPARATUS FOR DRINKING [73] Assignee: Moody Aquamatic Systems, Inc.,

Meadville, Pa.

[22] Filed: Aug. 20, 1971 [21] Appl. No; 173,552

Primary Examiner-John Adee Attorney-Shlesinger, Fitzsimmons & Shlesinger [57] ABSTRACT With this apparatus ozone gas is automatically applied to contaminated water in a contact tank, and is then transferred to a discharge tank in such manner that contaminated water cannot accidentally pass from one to the other tank, when the system is on automatic operation. Electrical controls responsive to sensing means disposed exteriorly of the contact tank, and responsive to predetermined changes in the weight or level of the water in the contact tank, automatically replenish the supply of ozonated water in the discharge tank, when necessary. A system is also disclosed for supplying ozone gas to a system selectively, and one at a time, from one of a plurality of ozone generators to prevent undue overloading of the generators, but the circuit to pump motor 46 may be temporarily interrupted as noted hereinafter.

8 Claims, 9 Drawing Figures PATENIEHJAN 8mm 3.784.008 sum 10F 4 FIG 9 INVENTOR.

VINCENT R. TROGLIONE FIG. 8 BY QJM;

ATTORNEYS PATENTEDJAN 8 m4 3.784.008

saw 3 or 4 IIO V. i N

PS-l m1 TMR-l L2 FIG. 7

FIG. 3

INVENTOR.

VINCENT R. TROGLIONE ATTORNEYS FIG. 6 FIG. 5

SOL-

INVENTOR. VINCENT R. TROGLIONE ATTORNEYS OZONATING APPARATUS FOR DRINKING WATER This invention relates to purification of drinking water, and more particularly to apparatus for automatically supplying ozone gas to drinking water supplies.

In various parts of the country supplies of pure, bacteria-free drinking water are not readily available. Moreover, even in areas where drinking water is purified in large quantities, for example, by municipal water supplies, even the so-called purified water often has undesirable tastes and/or odors because of undesirable residual concentrations of sulpher, chlorine, or the like. Heretofore various devices have been proposed for adding ozone gas to such water to improve its taste, and even to batches of contaminated water to remove impurities and bacteria therefrom. Such prior devices, however, have not been completely satisfactory, often because of the expense of manufacturing, installing and maintaining the equipment, and also because the equipment does not always preclude accidental mixing of contaminated batches of water with previously ozonated batches.

It is an object of this invention to provide improved apparatus for supplying ozone gas to drinking water to remove therefrom undesirable bacteria, contaminates and/or undesirable odors and tastes.

A further object of this invention is to provide improved ozonating apparatus capable of automatically and successively ozonating predetermined quantities of water for drinking purposes and the like.

A more specific object of this invention is to provide improved apparatus of the type described in which a quantity of water is ozonated in one tank, and automatically conveyed to another tank or reservoir to prevent incoming water from contaminating previously ozonated water.

Another object of this invention is to provide means for improving the efficiency of an ozone generator and apparatus of the type described by cooling the incoming air prior to its being delivered to the ozone generator.

Still another object of this invention is to provide novel ozonating apparatus which utilizes a plurality of different ozone generators that are successively and alternately energized to improve the efficiency thereof.

Other objects of the invention will be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is a schematic view of apparatus for ozonating drinking water in accordance with one embodiment of this invention;

FIG. 2 is a fragmentary rear view of a housing containing apparatus of the type illustrated in FIG. 1, portions of the housing being cut away and shown in section for purposes of illustration;

FIG. 3 is a fragmentary side elevational view of this housing and part of the equipment therein, portions again being cut away and shown in section;

FIG. 4 is a'wiring diagram illustrating schematically one manner in which this apparatus may be wired for operation;

FIG. 5 is a fragmentary, rear elevational view of another housing containing a modified form of the apparatus illustrated in FIG. 1, portions of the housing and the equipment therein again being broken away and shown in section for purposes of illustration;

FIG. 6 is a fragmentary side elevational view of the housing and apparatus shown in FIG. 5, portions thereof again being broken away;

FIG. 7 is a fragmentary side elevational view of part of the water level control mechanism shown in FIG. 5;

FIG. 8 is a schematic plan view of still another modification of this apparatus; and

FIG. 9 is a wiring diagram illustrating one manner in which the apparatus in FIG. 8 may be wired for operatron.

Referring now to the drawings by numerals of reference, and first to the embodiment shown in FIGS. 1 to 3, 20 denotes generally an ozonating unit comprising a cylindrical contact tank 21, which is mounted for limited vertical movement in a housing 22. A cap 24 on the lower end of tank 21 is seated on the upper end of a compression spring 25, the lower end of which is seated in a sleeve 26 mounted in the bottom of the housing. Adjacent its upper end, tank 21 passes through an annular strap 28, which is fastened at one point to the back of housing 22 to guide tank 21 for vertical movement in the housing.

Water is supplied to tank 21 from a flexible hose or pipe 30, which projects through a slot 31 in the back of housing 21, and which is connected through a normally-closed solenoid-operated valve 32 to a pressurized water supply provided, for example, by a well pump (not illustrated) or municipal water supply. Valve 32 is controlled by a solenoid SOL-l, which, when energized, opens the valve.

Mounted in the bottom of tank 21 is a conventional ozone gas diffuser 34, which is connected by a pipe 35 to the output of a conventional ozone generator 36 that is mounted in any desired manner in housing 22. Fresh air is supplied to the input of generator 36 by a pipe 37, which passes through a sealed opening in the lower end of tank 21, and vertically upwardly through the tank and out of a further sealed opening adjacent the upper end of the tank, and then through an air filter and dehumidifying unit 38, and pipe 39 to the input of the generator. As the incoming air passes upwardly through the pipe 37 in tank 21 the water in the tank cools the air before it reaches the generator 36.

As in the case of pipe 30, the pipes 35 and 37 must include a flexible section to allow vertical movement of tank 21 relative to generator 36.

In its upper end tank 21 has a vent opening connected through a pipe through pipe 41 and a filter 42 to atmosphere. Preferably filter 42 contains activated charcoal for removing excess ozone gas that may develop in the top of tank 21.

Adjacent its lower end tank 21 is connected by a pipe 44 and a conventional filter 45 with the input of a water pump 46 (FIG. 1), which may be mounted in any conventional manner in housing 22 adjacent tank 21. The output of pump 46 is connected by a pipe 47 to a sealed pressure tank 48, which is mounted in housing 22 adjacent tank 21, and which has the usual safety valve 49 in its upper end. The output of pump 46 is also connected by pipe 47 to a conventional, manuallyoperable valve or spigot 50, which is mounted in housing 22 to project downwardly from the upper end of a recess 52, which is formed in the front side of the housing to provide a support for a conventional jug or bottle 53 beneath valve 50.

As in the case of the pipes 30, 3S and 37, the pipe 44 has a flexible portion which permits tank 21 to move vertically relative to the pump 46 and tank 48.

Connected to pipe 47 to be responsive to the pressure in tank 48 is a conventional pressure switch PS-l, which may be selected to operate the water pump 46 within predetermined upper and lower pressure limits for tank 48. For example, the switch may be selected so that whenever the pressure in tank 48 falls below the predetermined lower limit of, for example, psi, the pump 46 will be made to operate, as disclosed in more detail hereinafter,-to pump water from tank 21 into tank 48 until the pressure therein reaches some predetermined value above 20 psi. Whenever the valve 50 is manipulated to withdraw water from the tank 48, the pressure in tank 48 drops in proportion to the quantity of water withdrawn from the tank.

The controls for supplying water to tank 21, and for actuating the ozone generator 36, are responsive to the weight of water in the contact tank 21, and as disclosed hereinafter, operate independently of the operation of the water pump 46. To provide this independent control two limit switches LS-l and LS-2 are mounted one above the other in housing 22 for operation by a trip plate 55, which is fastened to the upper end of tank 21 for movement therewith, and which projects into the vertical space between the two limit switches. Vertical movement of the tank 21 causes plate 55 to operate one or the other of these two limit switches as described hereinafter.

Referring now to FIG. 4, L1 and L2 denote two wires or lines adapted to be connected by a conventional, man ually-operable ON-OFF switch 57 to an alternating current (A.C.) power supply of, for example, 1 10 volts. The electric motor 46, which operates the pump 46, is connected in series with the switch PS-l between lines L1 and L2. Limit switch LS-1 has two normallyopen contacts A and B; and limit switch LS-2 has a single normally-closed contact. Contact A of LS-l is connected in series with a conventional timer unit TMR between the lines L1 and L2. Contact B of LS-l is connected in series with the normally-closed limit switch LS-2, and the solenoid SOL-1 between lines L1 and L2.

Also connected in parallel with the solenoid SOL-l between limit switch LS-Z and line L2 is the operating coil of a relay CR1. This relay controls a normally-open switch CR1-1, which is connected in parallel with the switch contact B of the limit switch LS-l. Also, the timer TMR controls a normally-open switch TMR-l, which is connected between the timer and line L1, and a normally-open switch TMR-2, which is connected in series with the ozone generator 36 between the lines L1 and L2.

in operation, when the switch 57 is closed, and assuming that tanks 21 and 48 are empty, tank 21 is urged by the spring 25 to it uppermost position, in which its plate 55 closes limit switch LS1. Also at this time the pressure in the tank 48 will be well below maximum, so that the switch PS-l will also be closed. Consequently, the now-closed contact A of switch LS-l energizes the timer TMR, which in turn closes switches TMR-1 and TMR-2 for a predetermined period of time, depending upon the specifications of the timer. Assuming the tank 21 has a capacity of, for example, gallons, then the timer TMR, which may be of the adjustable variety, may be set to maintain the switches TMR-1 and TMR-2 closed for approximately eight to twelve minutes.

The now-closed switch TMR-2 activates the generator 36, which begins to feed ozone gas to the diffuser 34 in tank 21. Also at this time contact B of switch LS-l is closed, so that both the solenoid SOL-1 and the relay CR1 are energized through the now-closed limit switch LS-2, thereby causing valve 32 to be opened to supply water to the tank 21. Relay CR1 now closes switch CR1-1. so that upon the subsequent downward movement of tank 21 and consequent opening of contact B, the solenoid SOL-1 and relay CR1 will nevertheless remain energized through the holding switch CR1-1 and the limit switch LS-2.

As the water in tank 21 reaches a predetermined upper level, the increasing weight of the tank causes it to settle in housing 22, thus compressing spring 25, and moving plate 55 downwardly to disengage LS-l, which returns to its open position. When the tank 21 has set tled far enough to cause plate 55 to engage and open switch LS-2, power to the solenoid SOL-1 and relay CR1 is interrupted, so that valve 32 closes to shut off the water supply to tank 21, and relay switch CR 1-1 reopens to prevent false energization of SOL-1 and the relay CR1 thrdugh the limit switch LS-2, when the contact tank 21 subsequently begins to rise as its contents are pumped into tank 48.

Once sufficient water has been withdrawn from tank 21 to cause the compression spring 25 once again to urge the tank upwardly far enough to close the limit switch LS-l, the process of refilling the tank 21, and ozonating the newly-added water is repeated in a manner that will be apparent from the above description.

From the foregoing it will be clear that, in addition to cooling the incoming air before it reaches the generator 36, the above-described apparatus also permits ozonated water to be pumped from the contact tank 21 into the separate pressure tank 48 by the pump 46 in response to the operation of the valve 50. Moreover, instead of being responsive to the pressure in the tank 48, as is the case with certain prior art apparatus, the above-described control mechanism enables the supply of water to the contact tank 21, and the supply of ozone gas into this tank, to be controlled by the weight of the water in the tank, independently of both the pressure in tank 48 and its pump 46.

A further advantage of this apparatus is that it permits isolation of the ozonated water in tank 48 from the water in contact tank 21. For example, assuming that switch PS-l is set to operate whenever six gallons of ozonated water have been drawn from the previously filled tank 48, and that tank 21 is filled when switch PS-l closes, then, during the pumping of water from tank 21 to tank 48 the rising tank 21 will not strike and close swtich LS-l until the pump 46 has completed filling tank 48. Consequently, pump 46 will not be operating during the subsequent period when valve 32 is open and admitting contaminated water to tank 21, so it will not be possible for contaminated water to be pumped to tank 48 before it has been completely ozonated.

To prevent simultaneous operation of pump 46, generator 36 and solenoid SOL-l during the initial filling of tank 21, a normally-closed manually operable pushbutton switch (not illustrated) may be inserted in series with switch PSI-1 and motor 46' to enable deenergization of the latter during the initial filling of tank 21.

Thereafter, tank 21 will always be full whenever the pump 46 is energized.

Referring now to the embodiment illustrated in FIGS. 5 to 7, wherein like numerals are employed to denote elements similar to those employed in the first embodiment, 60 denotes a housing containing a vertically disposed contact tank 61, and a vertical standpipe 62, which is mounted in the housing parallel to tank 61. As in the first embodiment, water is supplied to tank 61 through a normally-closed valve 32 that is controlled by a solenoid SOL-1. In this embodiment, however, the tank 61 is stationary and is connected at its lower end by a pipe 63 with the lower end of tank 62. Moreover, tank 62 has an overflow opening 64 (FIG. 5) in its upper end, which vents the standpipe to atmosphere, so that the water that is admitted to contact tank 61 passes through the pipe 63 to maintain the same water level L in both the contact tank and the standpipe.

Mounted in the lower end of tank 61 is a conventional ozone diffuser 66, which is connected to a pipe 67 that extends upwardly through the tank, and out of the upper end thereof to the output of an ozone generator 36 (FIG. 6), which may be mounted in any convenient position in housing 60. Also as in the first embodiment, an air supply pipe 68 for this ozone generator extends intermediate its ends longitudinally through tank 61, so that the air passing therethrough will be cooled before entering the generator. Also, a perforated filter 69 containing, for example, activated charcoal, is mounted in an opening in the upper end of tank 61 to vent the latter, and also to absorb any excess ozone gas that might be developed in the tank.

Mounted in the upper end of housing 60 adjacent the upper end of standpipe 62, and in registry therewith, is a cylindrical tank or reservoir 71, which is vented to atmosphere by a small pipe or nipple 72 (FIG. 6). Intermediate its ends tank 71 is connected to the standpipe 62 by a pipe 74. Tank 71, which may have a removable upper end, contains a disc-shaped filter 76, which is removably seated transversely across the center of the tank on an annular shoulder or collar 77 that is fastened to the inside of tank 71 coaxially thereof, and beneath the pipe 74. An outlet in the lower end of tank 71 is connected to a manually operable spigot or faucet 78 which, as in the first embodiment, projects downwardly into a recess 79 that is formed in the forward end of housing 60 to support a bottle or container beneath the spigot.

To control the admission of water to tank 61, a weight 81 (FIG. 5) is secured by a cord 82 to a ball float 83, which is mounted in the standpipe 62 to float on the water therein. Float 83 is connected at its upper end to one end of a further cord 85, which passes out of an opening in the top of the standpipe, and around a rotatable pulley 86, which is mounted on the upper end or cover of the standpipe. At its opposite end cord 85 extends downwardly along the outside of pipe 62 and has fastened to its other end a right-angular weight 87 (FIGS. 5 and 7), which is guided for vertical movement between a pair of spaced, parallel brackets 88 and 89, which are fastened to the outside of pipe 62 adjacent its upper end. Also mounted on pipe 62 adjacent opposite ends of the brackets 88 and 89 are two, vertically-spaced limit switches LS-l and LS-2, similar to those disclosed in the first embodiment. One arm of the right-angular weight 87 projects outwardly through the vertical slot formed by the confronting edges of brackets 88 and 89, and into the path of the operating arms of the switches LS-1 and LS-2 to operate the latter in a manner to be described hereinafter. A stop 90 is fastened to the upper ends of brackets 88 and 89 to limit the upward movement of weight 87.

To operate the apparatus of FIGS. 5 to 7, reference is again made to the wiring diagram of FIG. 4, which can be used to control also the apparatus of FIGS. 5 to 7, except, of course, that the pump 46 and the associated pressure switch PS-l are not utilized in the second embodiment, since the incoming water is fed by gravity from the contact tank 60 to the standpipe 62, and then to the supply tank 71.

At the start, and assuming that the contact tank 61 and standpipe 62 are empty, the weight 81, which is slightly heavier than the weight 87, will have descended in pipe 62 far enough to have caused weight 87 to be shifted upwardly between the brackets 88 and 89 to an upper limit position (FIG. 7) in which it engages the stop 90 and closes limit switch LS-l. Before closing the switch 57 (FIG. 4) to place the unit on automatic operation, a conventional valve (not illustrated) in pipe 63 is closed, and a manually operable valve (not illustrated) connected in by-pass' with valve 32 is opened, to supply contaminated water to tank 61 until it is filled. Generator 36 is then energized in any conventional manner by a separate circuit to ozonate the water in tank 61, after which the valve in line 63 is opened to admit the ozonated water to pipe 62. This process is repeated until all three tanks 61, 62 and 71 are filled with ozonated Water to level L, and the weight 87 has descended to trip switch LS-2 (FIG. 5).

At this time the valve in line 63 is opened, the by-pass valve for valve 32 is closed, and switch 57 (FIG. 4) is closed to place the unit in automatic operation. Switch LS-l is positioned so that when repeated operation of the valve 78 has caused the level of the water in the three tanks to fall to approximately the level of pipe 74, the weight 87 will have been elevated into contact once again with switch LS-l, thereby causing valve 32 to be opened, and also causing the ozone generator 36 to be energized as described above in connection with the first embodiment. The contaminated water entering tank 61 causes ozonated water in the bottom thereof to flow into pipe 62, which in turn overflows into tank 71 until ozonated water has risen in the pipe 62 high enough to cause the float 83 to return to its elevated position as illustrated in FIG. 5. Consequently the weight 87 will have fallen from its uppermost to its lowermost position (FIG. 5), in which it strikes limit switch LS-2, thereby to deenergize solenoid SOL-l, and to close valve 32 to shut off the water supply in a manner similar to that of the first embodiment. Eventually the timer TMR times out and automatically opens its switches TMR-l and TMR-2, thereby deenergizing the timer and returning it to its start position and also deenergizing the ozone generator 36. The system now remains static until sufficient water is drawn out of the spigot 78 to lower the water level to pipe 74.

When water is withdrawn from tank 71 by operation of spigot 78, the water in the lower half of the tank will already have passed through the filter 76; and any further water withdrawn from the tank will also have to pass through this filter. Preferably, therefore, this filter 76 contains activated charcoal for removing excess ozone gas from the water before its discharge from the spigot 78.

As in the first embodiment, during automatic operation of the system contaminated water cannot reach the discharge tank 71, because tank 71 is supplied by the standpipe 62, rather than receiving water directly from the contact tank 61. Before incoming water that enters the top of tank 61 can reach pipe 63 and enter pipe 62, it must be subjected to ozone gas dispensed by the diffuser 66.

When an ozone generator of the type employed in the above embodiments is operated for an extended pe riod of time the generator may become overheated, the electrodes become unduly corroded thereby reducing the output of the generator, and ultimately require premature maintenance or replacement. If, on the other hand the operation of the generator is intermittent heat does not cause corrosion or coating of the dielectric plates with foreign material prematurely and prolongs the service of the generator.

FIGS. 8 and 9 illustrate a modification of the system or unit disclosed in FIGS. to 7, which will obviate undesirable generator failure or shut-down time. In this modified system, wherein like numerals are employed to denote elements similar to those used in the preceeding embodiments, 61 and 61' denote a pair of contact tanks, which may be mounted in a housing 60 at opposite sides of a standpipe 62 of the type employed in the embodiment of FIGS. 5 to 7. Adjacent their lower ends the tanks 61 and 61 are connected through normallyclosed solenoid-operated valves 92 and 93 with the lower end of the standpipe 62. Adjacent its upper end pipe 62 is connected by the pipe 74 with a reservoir or discharge tank 71 also of the type employed in the preceeding embodiment. The outputs of two ozone generators 36-1 and 36-2 are connected through normallyclosed solenoid-operated valves 94 and 95 with the diffusers (not illustrated) that are mounted in the bottoms of tanks 61 and 61', respectively, in a manner that will be apparent from the preceding embodiment. The output of the water inlet valve 32 is connected through normally-closed solenoid-operated valves 96 and 97 to the tops of the contact tanks 61 and 61, respectively. Structurally the rest of the unit illustrated in FIG. 8 may be similar to that of the unit disclosed in FIGS. 5 to 7.

Referring now to FIG. 9, 98 denotes generally a conventional indexible selector switch having a moveable contact 98-1 connected at one end to a line L-l similar to that of FIG. 4, and selectively engageable at its opposite end with a pair of stationary contacts 98-2 and 98-3. In this embodiment a timer TMR, in addition to operating a switch TMR-l in the manner illustrated in FIG. 4, also operates two ozonating control. switches TMR-2 and TMR-3. Also, a relay CR1, which as in the embodiment of FIG. 4 is connected in parallel with the solenoid SOL-l that operates the water supply valve 32, controls two additional normallyopen switches CR1-2 and CR1-3. Also in this embodiment the valves 92, 94 and 96 are controlled by solenoids SOL-2, SOL-3 and SOL-4, respectively; and the valves 93, 95 and 97 are controlled by solenoids SOL-5, SOL-6 and SOL-7, respectively.

As shown in FIG. 9, the stationary contact 98-2 is connected through the timer switch TMR-2 with the generator 36-1 and the solenoid SOL-3, which are connected in parallel between switch TMR-2 and line L2. Contact 98-2 is also connected through switch CR1-2 and solenoid SOL-4 with line L2, and directly through solenoid SOL-2 with line L2. Contact 98-3 is connected through the third timer switch TMR-3 with the generator 36-2 and solenoid SOL-6, which are connected in parallel between this timer switch and the line L2; and contact 98-3 is also connected through switch CR1-3 and solenoid SOL-7 with line L2, and directly through solenoid SOL-5 with the line L2.

In operation, and assuming for purposes of description that the indexible switch 98 is of the manuallyoperable variety, the operator selects one generator or the other by moving contact 98-1 into engagement, for example, with stationary contact 98-2 as shown in FIG. 9. Then, whenever the switch LS-l is closed, the timer TMR and the relay coil CR1 close their associated switches, thereby energizing generator 36-1 and the solenoids SOL-2,,SOL-3 and SOL-4, thus opening the associated valves 92, 94 and 96 to supply ozone gas and fresh water'to the contact tank 61, and hence to the standpipe 62. At this time contact 98-3 is deenergized, so that valves 93, and 97 remain closed, thereby maintaining the generator 36-2 deenergized, and isolating contact tank 61 from the water supply, and from the standpipe 62.

When the tank 61 and the standpipe 62 are full, the relay CR1 is deenergized in a manner that will be apparent from the above description, thus deenergizing solenoid SOL-4 to close off the water supply tank 61. Solenoid SOL-2, however, remains energized to keep valve 92 open so that tank 61 remains in communication with the standpipe 62. When the timer TMR times out, the switch TMR-2 opens, as noted above, to deenergize the the generator 36-1, and solenoid SOL-3.

The supply of ozone from the generator 36-1, and water from the output of the main water control valve 32 continues to be controlled by the limit switches LS-l and LS-2 in a manner that will be apparent from the above description, until such time as the switch 98-1 is swung into engagement with contact 98-3. At this time the solenoid SOL-2 is deenergized to close valve 92 and isolate tank 61 from the tube 62', and ozone gas and water are then supplied to the tank 61', when necessary, under the control of the same pair of limit switches LS-l and LS-2. When power is supplied to the contact 98-3, solenoid SOL-5 is energized to open valve 93 and connect the bottom of contact tank 61 to the bottom of tube 62; and the ozone generator 36-2 and water control valve 97 are controlled by the timer switch TMR-3 and the relay switch CR1-3 in a manner that will be apparent from the above description.

While in the embodiment illustrated in FIGS. 8 and 9 only two ozone generators and contact tanks are employed, it will be apparent to one skilled in the art that the apparatus in FIG. 8, and the associated controls as shown in FIG. 9, can be readily modified to accommodate several additional ozone generators, and contact tanks if necessary, to supply water to the standpipe 62. Moreover, while a plurality of contact tanks are shown in FIGS. 8 and 9, it will be apparent that a plurality of ozone generators could be connected selectively to a single contact tank for intermittent operation under control of an indexible switch of the type illustrated at 98 so that the same contact tank may be supplied with ozone gasintermittently from different generators.

From the foregoing it will be apparent that the instant invention provides ready and simple means for cooling incoming air prior to its entry into the ozone generators in units of the type described, thereby to increase the efficiency of the generators. Moreover, by using for the same ozonating unit a plurality of ozone generators that are selectively operated one at a time, the operating lives of the generators are prolonged, and undesirable shut-down time of the unit for maintenance purposes is reduced considerably. Furthermore, by ozonating water in one tank, and feeding the ozonated water, ei-

ther by gravity or pump, to a second tank, the automatic control of the ozonated water supply and ozone generator can be readily controlled by apparatus located outside of the contact tank, thus prolonging the life of the control apparatus. Furthermore, each of the embodiments herein disclosed enables the contact tank operatively to be isolated from the discharge or storage tank, so that contaminated water cannot pass from the contact tank to the storage tank.

While the invention herein describes apparatus to purify drinking water, the water may be used for cooling, mixing, ice making or other purposes for which purified water is required. Also, water level in tanks where the water system is controlled by weight or float may be also controlled by a pressure switch of the bellows type or the like.

Having thus described my invention, what I claim is:

1. Apparatus for purifying drinking water, comprising a pair of tanks, at least one of which is vented to atmosphere,

first valve means electrically actuatable to supply water to said one tank,

a diffuser mounted in said one tank adjacent its lower end,

an ozone generator electrically actuatable to supply ozone gas to said diffuser to be distributed thereby to the water in said one tank,

means connecting together said tanks to convey ozonated water from said one to the other of said tanks,

second valve means for withdrawing water from said other tank,

a pair of spaced switches mounted externally of said tanks for controlling the operations of said generator and said first valve means,

switch operating means including an actuating member mounted to reciprocate between said switches and a first limit position in which said member operates one of said switches when the quantity of water in said one tank falls below a first value, and to operate the other of said switches when said quantity of water in said one tank increases a predetermined amount above said first value, and

circuit means connected to said switches and responsive to the operation of said one switch to actuate said generator and said first valve-means to feed ozone gas and water, respectively, to said one tank, and operative upon the operation of said other switch to deactuate said first valve means,

said circuit means including means operative each time said one switch is operated to actuate said generator for a predetermined period of time independently of the oepration of said other switch.

2. Apparatus as defined in claim 1, including a conduit connected at one end to an air supply and at its opposite end to the inlet of said generator,

said conduit having a portion thereof extendingly longitudinally through said one tank and the water therein, whereby the air in said conduit is cooled by the water in said one tank before reaching said generator.

3. Apparatus as defined in claim 1, including means mounting said one tank for vertical movement, and

resilient means connected to said one tank to resist downward movement thereof upon admission of water to said one tank, and operative to shift said one tank upwardly upon withdrawal of water therefrom,

said switch actuating member being connected to said one tank for movement thereby selectively into engagement with said switches as the quantity of the water in said one tank changes.

4. Apparatus as defined in claim 1, wherein said connecting means comprises a pump for pumping water from said one to said other tank,

a pressure switch connected in said circuit means and responsive to the pressure in said other tank momentarily to operate said pump, independently of the two first-named switches, whenever the pressure in said other tank falls below a predetermined value, and

means mounting said one switch for operation by said actuating member immediately following each operation of said pump. I

5. Apparatus as defined in claim 1, wherein said actuating member is mounted on the outside of said other tank for movement in opposite directions between said switches to operate the latter,

a second, buoyant member is mounted in said other tank to float on the water therein, and to move vertically in said other tank as the level of the water therein changes, and

means connects said members to transmit the motion of said second member to said actuating member.

6. Apparatus as defined in claim 1, wherein said means connecting said tanks comprises a first pipe opening at opposite ends on the interiors of said tanks adjacent the lower ends thereof,

a third tank is mounted adjacent said other tank and is connected intermediate its ends by a second pipe with said other tank above said first pipe to receive water from said other tank,

all three of said tanks are vented to atmosphere, and

said one switch is positioned to be operated by said actuating member when the level of the water in said third tank falls below said second pipe.

7. Apparatus as defined in claim 6, wherein said manually operable valve means is connected to said third tank adjacent the lower end thereof, and

a filter is mounted in said third tank between said second pipe and said manually operable valve means to filter water before the latter is discharged from said third tank.

8. Apparatus for purifying drinking water, comprising a container for water,

means including a first, normally-closed valve operable to supply water to said container,

a second valve operable to withdraw water from said container,

electrical control means connected to said water supply means and responsive to predetermined changes in the quantity of water in said container automatically to open said first valve to replenish the supply of water in said container each time said quantity falls beiow a predetermined value,

a plurality of separate ozone generators, and

a normally-closed outlet valve interposed between each generator and said water supply means and operative, when open, to connect the output of the associated generator to said water supply means,

said control means including selector means for selectively energizing one of said generators and opening its associated outlet valve each time said first valve is opened,

said selector means comprising a manualiy-indexible selector switch movable selectively to a plurality of different positions in each of which it connects a energized. 

1. Apparatus for purifying drinking water, comprising a pair of tanks, at least one of which is vented to atmosphere, first valve means electrically actuatable to supply water to said one tank, a diffuser mounted in said one tank adjacent its lower end, an ozone generator electrically actuatable to supply ozone gas to said diffuser to be distributed thereby to the water in said one tank, means connecting together said tanks to convey ozonated water from said one to the other of said tanks, second valve means for withdrawing water from said other tank, a pair of spaced switches mounted externally of said tanks for controlling the operations of said generator and said first valve means, switch operating means including an actuating member mounted to reciprocate between said switches and a first limit position in which said member operates one of said switches when the quantity of water in said one tank falls below a first value, and to operate the other of said switches when said quantity of water in said one tank increases a predetermined amount above said first value, and circuit means connected to said switches and responsive to the operation of said one switch to actuate said generator and said first valve means to feed ozone gas and water, respectively, to said one tank, and operative upon the operation of said other switch to deactuate said first valve means, said circuit means including means operative each time said one switch is operated to actuate said generator for a predetermined period of time independently of the oepration of said other switch.
 2. Apparatus as defined in claim 1, including a conduit connected at one end to an air supply and at its opposite end to the inlet of said generator, said conduit having a portion thereof extendingly longitudinally through said one tank and the water therein, whereby the air in said conduit is cooled by the water in said one tank before reaching said generator.
 3. Apparatus as defined in claim 1, including means mounting said one tank for vertical movement, and resilient means connected to said one tank to resist downward movement thereof upon admission of water to said one tank, and operative to shift said one tank upwardly upon withdrawal of water therefrom, said switch actuating member being connected to said one tank for movement thereby selectively into engagement with said switches as the quantity of the water in said one tank changes.
 4. Apparatus as defined in claim 1, wherein said connecting means comprises a pump for pumping water from said one to said other tank, a pressure switch connected in said circuit means and responsive to the pressure in said other tank momentarily to operate said pump, independently of the two first-named switches, whenever the pressure in said other tank falls below a predetermined value, and means mounting said one switch for operation by said actuating member immediately following each operation of said pump.
 5. Apparatus as defined in claim 1, wherein said actuating member is mounted on the outside of said other tank for movement in opposite directions between said switches to operate the latter, a second, buoyant member is mounted in said other tank to float on the water therein, and to move vertically in said other tank as the level of the water therein changes, and means connects said members to transmit the motion of said second member to said actuating member.
 6. Apparatus as defined in claim 1, wherein said means connecting said tanks comprises a first pipe opening at opposite ends on the interiors of said tanks adjacent the lower ends thereof, a third tank is mounted adjacent said other tank and is connected intermediate its ends by a second pipe with said other tank above said first pipe to receive water from said other tank, all three of said tanks are vented to atmosphere, and said one switch is positioned to be operated by said actuating member when the level of the water in said third tank falls below said second pipe.
 7. Apparatus as defined in claim 6, wherein said manually operable valve means is connected to said third tank adjacent the lower end thereof, and a filter is mounted in said third tank between said second pipe and said manually operable valve means to filter water before the latter is discharged from said third tank.
 8. Apparatus for purifying drinking water, comprising a container for water, means including a first, normally-closed valve operable to supply water to said container, a second valve operable to withdraw water from said container, electrical control means connected to said water supply means and responsive to predetermined changes in the quantity of water in said container automatically to open said first valve to replenish the supply of water in said container each time said quantity falls below a predetermined value, a plurality of separate ozone generators, and a normally-closed outlet valve interposed between each generator and said water supply means and operative, when open, to connect the output of the associated generator to said water supply means, said control means including selector means for selectively energizing one of said generators and opening its associated outlet valve each time said first valve is opened, said selector means comprising a manually-indexible selector switch movable selectively to a plurality of different posItions in each of which it connects a different one of said generators and outlet valves in circuit with said control means, said water supply means including a first solenoid operative, when energized to open said first valve, said control means further including first switch means connected in circuit with said first solenoid to energize the latter each time the quantity of water in said container falls below said predetermined value, and said selector means including second switch means operative to energize said one generator for a predetermined interval each time said first solenoid is energized. 